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Aug. 25, 1936. H. N. DURHAM MECHANISM FOR SEPARATING INTERMIXED DIVIDED MATERIALS Original Filed Aug. 5, 1931.

ATTORNE talities and combinations ingtoFig. 1.

.No..'555,16l," August 5, "1931. Application v aaasu-al No; 25.989 veland mechanism. for sepmtingintermixed, divided 3. WW a novel process and mechanism having ap-' 5 plicability for purifying "run-of-the -mine coal;

' 'lheinvention relates tea no materials, and more particularly Objects and advantages of the invention will be set forth in part hereinafter andi in part.- will be obvious herefrom, or vmaybe learned by practice with the invention, the samebeing real-' being ized and attained by means of the instrumenpointed out'inthe appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and im-' provements herein shown and described.

The accompanying drawing, referred to herein and constituting a part hereof, illustrates one embodiment of the invention, and together with the description, serves to of the invention.

Of the drawinsz- Fig. 1 isa longitudinal, vertical section through a mechanism embodying the invention;

Fig. 2 is a partial vertical, longitudinal section of a modification, and corresponds to the central part of Fig. 1; and

Fig. 3 is a fragmentary top plan, correspond- The invention relates to a novel and improved mechanism especially capacitated for separating intermixed broken, or other finely divided, ma terials varying widely in range of'sizes of the pieces or particles, and some "at least of the intermixed materials varying but little in their specific gravities. An intermixture of this kind to which the invention is particularly'applicable, is raw or impure coal as it comes from .the mine, with only the very large lumps or pieces crushed or removed. That is, effective and satisfactorycommercial purification of such coal is efi'ected without the costly and cumbersome presizingwhich is widely practiced, and which has been necessary in the greater part of the prior art processes and mechanisms Due to the concurrent wide size range of the pieces, and the close approximation in specific gravities of the intermixed materials, successful and efiicient commercial separation, such as purification of run-of-mine coal above-referred to, present a problem of great practical difiiculty, especially in view of the commercial requirements for an exceedingly close approximation to the washability curves, or fioat-and-sink' tests.

The invention employs as the separating explain the principles 7 Sanders" B;

"ncy orf dry, fiuid or" fiuid'agency, of variably-predeterminable .spe-

ciflc gravity. I employ as the'present preferred, form, a .dry; finely-divided or otherwise particulate materiai'through which air, or other gas,

.; is;infil trated to render it thoroughly fluid, and j in such 'regu'lated'proportion as to securea specificgravity which will establish and maintain the desired splitting point for the particular coal The most emcient dry fiuid medium,- so far as now known, consists of finely particulate material, such as sand orvery fine coal, into which; U

a regulated quantity of air is infiltrated to impart practically complete fiuid properties to the l infiltrated material, and at the same time to give a specific gravity to the dry fluid medium between that of the lightest material-of one separated group and that of the heaviest material of the other separated group, or a specific I gravity which in cooperation with currents or fiowage movement likewise created in the fiuid medium will efi'ect a separation of Y the intermixed materials at the required or desired split ltl a p int. I

. 2 By my invention there is maintained as the coal purifying instrumentality, a body of particulate fiuidic medium, comprising preferably sand or fine coal, rendered more completely fiuidic and of a proper specific gravity by regu 30 lated' infiltration of air, so as to constitute a sink and fioat medium for the coal being purified; and cooperating with the foregoing, a current is mechanically created and maintained within the upper part of the body of fiuidic me- 35 dium, which further acts dynamically and agitatiohally upon the coal to impart a forward propulsive efi'ect and to facilitate and increase the separating action. The refuse, which is of heavier specific gravity than the fiuidic medium will sink downwardly therethrough, and the lighter coal will fioat upon or within the fiuidic I medium, and will also be impelled to the discharge locus by the current action, and separation and purification is thereby effected. .The4 current fiow, created directly in theupper part of the fiuidic medium, and moving from the feed locus to the discharge locus of the coal, acts indirectly on the coal through the agency ofthe fiuidic medium. This current action of 50 the fiuidic medium impels forwardly the vbed of coal undergoing separation and purification without in any wise disturbing or impairing the coaction of the coal and fiuidic medium in the aeparating'or purifying operation. In addition to eifecting the relatively rapid progression of the coal without impairment of the separating action, the current flow also provides as an element or component of the separating and purii'ying process the dynamic or stream eiiectof the fiuid medium, and as an additional purifying factor, an agitational and loosening action of the fluidic medium on the coal- More particularly,-by my invention, there is maintained a body of fluidic material having the characteristics described and acting as a sink and iioat fluidic medium, in the process of purifying the bed of coal. Mechanical means are provided, acting directly in the upper part of the body of fluidic medium, to create and maintain a current of the fluidic medium moving from the feeding-on locus to the discharge locus of the bed of coal, with regulable speed control for said mechanical means to correspondingly control the current action. By the mechanical creation and regulation of the current flow within the fluidic medium, a corresponding nice. and comprehensive control is effected of the positive forward progression of the bed of coal; of the concurrent dynamic, stream-likeseparation action; and also of the fluidic agitation, acting directly on the bed of coal, which promotes and accelerates the separating action. The relatively quiescent inferior body of the fluidic medium acts as a support to the surface current and agitation as well as a sink and float medium or agency.

It will be understood that the foregoing gen-- eral description of the invention, and the following detailed description as well, are illustrative and exemplary, but are. not restrictive of the invention.

Referring now in detail to'the embodiment of the invention illustrated by way of example in the accompanying drawing, a table I is pros vided for the bed of iiuldic medium, the table comprising a rear wall 8, side walls I and a front wall 8. The bottom 9 of the table is of air-pervious material, which is connected at its upper edges to the side and end walls of the table, and is inclined downwardly and inwardly therefrom to a central refuse discharge orifice III. The orifice l communicates with a downwardly-inclined refuse discharge chute H, which passes through and projects outwardly from the bottom of the air chamber. The refuse discharge chute is preferably provided with discharge regu atinfl gate I1, pivotally supported at I 3, and having a counterweight ll. The refuse is discharged onto a vibrating screen II, where it is desanded, the refuse being conveyed away and the sand being recirculated. For the purpose of regulating the depth of the surface current, and the head imposed on the fluidic medium, the front or discharge top edge of the tableis regulable in height by suitable means, and as shown a front board 23 is mounted on the front wall I by means of vertically disposed bolt and slot connections 24. A discharge chute 2! is' also provided which discharges the purified coal onto a vibrating screen 20, where the sand is removed, and then recirculated. A vertically adjustable skimmer may be provided within the bed, if desired, for effecting a split between-the bottom of the current of purified coal and the sand.

Means are provided for infiltrating air into the particulate fluid material, and means are capacitated to provide local regulation of the air infiltration in the different parts of the fluidic body. As embodied, an air chamber 38 is provided beneath the table, to which the air is supplied through a conduit 34 from a fan, or other suitable source of supply, and from which chamber the air supplied for the fluidic medium may be-nicely regulated as required. Just beneath the air-pervious bottom 9 of the table is a floor 35, provided with a relatively large number of air-passing apertures 38, which may be optionally left open or closed by suitable means such as corks 31. Above the floor 35, and extending from itto the air-pervious bottom ii, are a plurality of vertically-disposed partitions 38, which divide the intervening space into any desired number of chambers, within which the passage of the air, and the air action upon the bed of particulate fluidic material, may beindependently regulated as desired by means of the number of corks 31 used in the various chambers.

Means are provided for proportionally feeding the raw coal to the surface of the fluidic medium, and as embodied a hopper 41 for the raw coal is provided, having a variable speed feeding device 48, which may be of any standard or other suitable form, whereby the raw coal is accurately fed at a predetermined rate to the bed of fluidic material, and the rate of feed may be regulated to the point of greatest emciency for the particular kind of coal and the conditions of separation.

Means are provided by the invention, operating within the upper part of the bed of fluid ma terials for creating and maintaining a positive current of the fluidic material from the feedingon locus of the coal to the place of discharge. As embodied in Fig. 1, a plurality of wedgeshaped plates are arranged cross-wise of the bed of fluidic material, and in a horizontal series extending lengthwise of the bed, the blades being the plates beneath the surface of the-medium may be regulated as desired or found to be most efllcient. The sharp edges of the plates ii are at the rear, and they have flat vertical faces 52 along the front side thereof. Thus as the series of plates are rapidly reciprocated they positively impel the fluidic medium forwardly when moving in that direction, but due to their sharp rear edges, the plates cut backwardly through the fluidic medium on their return stroke without causing appreciable motion of the medium.

Suitable means are provided for reciprocating the current creating plates El, and as embodied, they are mounted in side frames II, which are reciprocablehorizontally in guides 54, mounted on the side wall I on the table. In the embodied form of actuating means, eccentric rods 55 are shown pivotally connected to the rear end of the frames 53, and the eccentrics Ii are mounted on a shaft 51. The shaft 51 is provided withany suitable form of variable speed drive I. By varying the speed of the drive, the speed of the plates 5| may be correspondingly regulated to create the current eifect desired. The sand, or other particularmaterial, screened out from the refuse and from the coal may be recirculated, and suificient sand may be fed in with the raw coal to make good any losses.

In ,Fig. 2 a diflerent form of current creating device is shown, comprising a series of angularly movable blades 64, mounted on shafts 85, mounted the forward movement of the frame 83 to impel 75 7 iv I a 2o',oaa' the fluidic medium forwardly in a current,

blades moving'to a substantially horizontal posi-v tion on the reverse stroke, so as to cut, backwardly inactively through the fluid medium, and to disturb the current flow as little as possible.

To impartuthe desired angular-'moticn. to the 1 blades N, there is provided on the shaft ,8, at

j -rent creatingstroke. The action of the fluidic medium will swing the plates {I to the horizontal one side,'downwardly projecting tails or trips, which at the rear'end. of the strokeof the'frame Il engage pins 81 projecting inwardly from the a side walls 1 offthe table, .to raise the plates to vertical position preparatory for the forwardcurposition for the return movement.

With either'of these current creating devices there may. be used, if desired, current directing plates 'II, which may be dispowd at any position and inclination in the fluidic medium beneath the frames 53, by any suitable means, such as bolt and slot. connections, to direct the pressure and flow of fluidic-medium upwardly and for- -wardly as may be'desired. The premure of the underlying body of fluidic medium,- and the upwardly rising or boiling action of the infiltrated air will however create substantially the same. effect, and in many cases to a suilicient'degree,

without the'us of the plates. I

By my invention there is secured the full and highly efficient sink and float separating action of a deep bed of the particulate fluidic medium,

and at the same time the mechanical propulsive eifect required to progress the coal over the fluidic body as rapidly as possible consistentwith the highest ,eficient purifying capacity of the table. At the same time, all disturbance of the relation of the coal and fluidic medium is avoided. There is no dragging of the coal across the surface of I the fluidic medium, nor any other disturbance of-the relation indicated. On the other hand.

the forward impulsion of the coal by the flow of the fluidic medium in which it is immersed, and by which it is floated, effects the required forward progression of the coal from the feeding locus to the discharge locus and at the same time gains a higher degree of separating andpurifying emciency through the dynamic and agitational action of the flowing fluidic medium on the coal immersed therein and sustained thereby.

The invention as exemplar-fly disclosed is ap plied only to a primary table, but it may be appliedin like manner to a retreatment system involving any number of tables.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages. a

What I claim is:

1. A mechanism for purifying coal including in combination means for maintaining a quiescent bodyof a dry, particulate gas-distended fluidic medium, means for feeding raw coal to the surface of said medium, means acting within the medium for creating a shallow current flowing across the top of the body to propel the coal thereacross, and means for collecting refuse which has settled below the surface-current and into the quiscent body.

2. A mechanism for purifying coal including in combination means for maintaining a. quiescent body of a dry, particulate gas-distended fluidic medium, means for feeding raw coal to the surface'ofsald medium, meanscomprising a reciprocatory immune device acting within, the me-,

dium. ior'creating a currenttfflowing across the top of the body to propel the'coal thereacross, and means for collecting refuse'which has settled below'the surface'currentand into the quiscent body of 'a dry, particulate gas-distended fluidic medium, means for feeding raw coal to the surfaceof said medium, means. comprising a reciprocatory impelling device operable in one directo propel the coal thereacross, and means for collecting refuse which has settled below the surface current and into the quiscent body.

4. A mechanism for purifying coal including in combination meansvfor maintaining a quiscent body of a dry, particulate gas-distended fluidic medium, means for feeding raw coal to the surface of said medium, means comprising spacedapart mechanical impelling' means acting within the medium for creating a shallow current flowing across the top of the body to propel the coal thereacross, and means for collecting refuse which has settled below the surface current and into the quiscent body.

5. Ida mechanism for purifying coal in combination a stationary air-pervious table for maintaining a bed of dry,-gas-distended fiuidic material of substantial depth, means for feeding impure coalto the surface of said bed to undergo stratification andseparation within said fluidbed, and means for eflecting an agitational and loosening action on the bed comprising a relatively shallow member movable back and forth in a shallow layer below the surface of the bed.

6. In a mechanism for purifying coal in combination a stationary air-pervious table for maintaining a, bed of dry-gas-distended fluidic mate rial of substantial 'depth. means for feeding impure coal to the surface of said bed to undergo stratification and separation within said fluidized bed, and means for effecting an agitational 3. Amechanismifor purifying'coal including inv combination mea'nsifor maintaining a quiscent .tion only and acting within the'medium for creating a current flowing across the top of the body and loosening action on the bed comprising a relatively shallow member reciprocating substantially parallel to the surface of the bed and oversubstantially the same path in both directions.

7. In a mechanism for purifying coal in combination a stationary air-pervious table for maintaining a bed of dry, gas-distended fluidic material of substantial depth, means for feeding impure coal to the surface of said bed to undergo Stratification and separation-within said fluidized bed, and means for eiIectiing an agitational and loosening action on the bed comprising an apertured air-pervious member movable back and forth in a shallow layer below the surface of the bed 8: In a mechanism for purifying coal in combination a stationary air-pervious table for maintaining a bed of dry. gas-distended fluidic material oi substantial depth, means for feeding impure coal to the surface of said bed to' undergo stratification and separation within said fluidized bed, means for effecting an agitational and loosening action on the bed comprising a relatively shallow reciprocating, apertured member through which material in the bed may settle, said member being movable in a plane below'the surface of the bed, means for discharging a flotant stratum of purified coal from the table above said member and means for discharging settled ".refuse from the table below said member.

9. In a mechanism for purifying coal in combination a stationary 'air-pervious table for maintaining a bed of dry. flfle-distended'iiuidic. mate-. rial of substantial depth, means for feeding impure coal to the surface of said bed-to undergo stratification and separation within saidfluidized bed, means for effecting an agitational and loosening action on the bed comprising a rela-' tively shallow reciprocating, apertured member through which material in the bed may settle.

" said member being movable in a plane below the surface of the bed, means for discharging a flotant stratum of coal from the end of the table ized bed, means for effecting an agitational and.

loosening action on the bed comprising a reciproeating, apertured member movable in a shallow path below and substantially parallel to the surface of the bed, means for discharging a flotant stratum of coal from the end of the table remote from the feed endand above said reciprocating member, and means for discharging settled refuse by gravity from the same end of the table-and below said member.

some

11. In a mechanism for purifying coal in combination a relatively long and narrow. stationary air-pervious table, having a sloping bottom; for maintaining a bed of dry, gas-distended fiuidic material of substantial depth, means for feeding impure coal to the surface of said bed at the rear end thereof to undergo stratification and separation within said fluidized bed, means for effecting an agitational and loosening action on the bed comprising a reciprocating, apertured,

shallow member movable in a shallow layer below the surface of the bed, means for discharging a flotant stratum of coal from the end of the table remote from the feed and and above said reciprocating member, and means for discharging settled refuse from the same end of the table and below saldmember.

12, In a mechanism for purifying coal in com-- bination a stationary air-pervious table for maintaining a, bed of dry, gas-distended fluidic material of substantial depth, means for feeding impure coal to the surface of said bed to undergo stratification and separation within said fluidized bed. means for effecting an agitational and loosening action on the bed comprising a reciprocating, apertured, shallow member movable in a shallow layer below the surface of the bed, means for discharging a flctant stratum of coal from the table at the end remote from the feed and above said reciprocating member, means for moving settled refuse by gravity along the bottom of the table, and pressure-regulated means at the same end of the table for controlling the discharge of said refuse.

HOBART N. DURHAM. 

